<?php
if( !defined('BASE') ) exit('Access Denied!');
/**
 * Obullo Framework (c) 2009.
 *
 * PHP5 MVC Framework software for PHP 5.2.4 or newer
 *
 * @package         obullo       
 * @author          obullo.com
 * @copyright       Ersin Güvenç (c) 2009.
 * @license         http://obullo.com/manual/license 
 * @since           Version 1.0
 * @filesource
 * @license
 */

// ------------------------------------------------------------------------

/**
 * Obullo Captcha Helper
 * Derived From Code Igniter Captcha Plugin
 *
 * @package     Obullo
 * @subpackage  Helpers
 * @category    Helpers
 * @author      ExpressionEngine Dev Team
 * @author      Ersin Güvenç
 * @link        
 */

/*
Instructions:

Load the base helper using:

     loader::base_helper('captcha');

Once loaded you can generate a captcha like this:
    
    $vals = array(
                    'max_char'   => '5',
                    'img_path'   => 'captcha/',
                    'img_url'    => $this->base.'/sources/captcha/',
                    'font_path'  => 'sources/fonts/Lucida-Console.ttf',
                    'img_width'  => '200',
                    'img_height' => 30,
                    'expiration' => 7200,
                    'background' => '#FFFFFF',
                    'border'     => '#CCCCCC',
                    'text'       => '#0033cc',
                    'grid'       => '#0033cc',
                    'shadow'     => '#0033cc',
                    'pool'       => '123456789ABCDEFGHIJKLMNPRSTUVWXYZ',
                );
    
    $cap = create_captcha($vals);
    echo $cap['image'];
    

NOTES:
    
    The captcha function requires the GD image library.
    
    Only the img_path and img_url are required.
    
    If a "word" is not supplied, the function will generate a random
    ASCII string.  You might put together your own word library that
    you can draw randomly from.
    
    If you do not specify a path to a TRUE TYPE font, the native ugly GD
    font will be used.
    
    The "captcha" folder must be writable (666, or 777)
    
    The "expiration" (in seconds) signifies how long an image will
    remain in the captcha folder before it will be deleted.  The default
    is two hours.

RETURNED DATA

The create_captcha() function returns an associative array with this data:

  [array]
  (
    'image' => IMAGE TAG
    'time'    => TIMESTAMP (in microtime)
    'word'    => CAPTCHA WORD
  )

The "image" is the actual image tag:
<img src="http://example.com/captcha/12345.jpg" width="140" height="50" />

The "time" is the micro timestamp used as the image name without the file
extension.  It will be a number like this:  1139612155.3422

The "word" is the word that appears in the captcha image, which if not
supplied to the function, will be a random string.


ADDING A DATABASE

In order for the captcha function to prevent someone from posting, you will need
to add the information returned from create_captcha() function to your database.
Then, when the data from the form is submitted by the user you will need to verify
that the data exists in the database and has not expired.

Here is a table prototype:

    CREATE TABLE captcha (
     captcha_id bigint(13) unsigned NOT NULL auto_increment,
     captcha_time int(10) unsigned NOT NULL,
     ip_address varchar(16) default '0' NOT NULL,
     word varchar(20) NOT NULL,
     PRIMARY KEY `captcha_id` (`captcha_id`),
     KEY `word` (`word`)
    )


Here is an example of usage with a DB.

On the page where the captcha will be shown you'll have something like this:

    loader::base_helper('captcha');
    $vals = array(
                    'img_path'     => './captcha/',
                    'img_url'     => 'http://example.com/captcha/'
                );
    
    $cap = create_captcha($vals);

    $data = array(
                    'captcha_id'    => '',
                    'captcha_time'    => $cap['time'],
                    'ip_address'    => $this->input->ip_address(),
                    'word'            => $cap['word']
                );

    $query = $this->db->insert('captcha', $data);
        
    echo 'Submit the word you see below:';
    echo $cap['image'];
    echo '<input type="text" name="captcha" value="" />';


Then, on the page that accepts the submission you'll have something like this:

    // First, delete old captchas
    $expiration = time()-7200; // Two hour limit
    $DB->query("DELETE FROM captcha WHERE captcha_time < ".$expiration);        

    // Then see if a captcha exists:
    $sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND date > ?";
    $binds = array($_POST['captcha'], $this->input->ip_address(), $expiration);
    $query = $this->db->query($sql, $binds);
    $row = $query->row();

    if ($row->count == 0)
    {
        echo "You must submit the word that appears in the image";
    }

*/

/**
|==========================================================
| Convert HEX Colors to RGB
|==========================================================
|
*/
function html2rgb($color)
{
    if ($color[0] == '#')
        $color = substr($color, 1);

    if (strlen($color) == 6)
        list($r, $g, $b) = array($color[0].$color[1],
                                 $color[2].$color[3],
                                 $color[4].$color[5]);
    elseif (strlen($color) == 3)
        list($r, $g, $b) = array($color[0].$color[0], $color[1].$color[1], $color[2].$color[2]);
    else
        return false;

    $r = hexdec($r); $g = hexdec($g); $b = hexdec($b);

    return array($r, $g, $b);
}
    
/**
|==========================================================
| Create Captcha
|==========================================================
|
*/
function create_captcha($data = '', $img_path = '', $img_url = '', $font_path = '')
{        
    $defaults = array(
    'word'      => '',
    'max_char'  => '6',
    'img_path'  => '',
    'img_url'   => '',
    'img_width' => '150',
    'img_height'=> '30',
    'font_path' => '',
    'expiration'=> 7200,
     // colors 
    'background' => '#FFFFFF',
    'border'     => '#CCCCCC',
    'text'       => '#330099',
    'grid'       => '#0033CC',
    'shadow'     => '#330099',
    // pool
    'pool'       => '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
    );        
    
    foreach ($defaults as $key => $val)
    {
        if ( ! is_array($data))
        {
            if ( ! isset($$key) OR $$key == '')
            {
                $$key = $val;
            }
        }
        else
        {            
            $$key = ( ! isset($data[$key])) ? $val : $data[$key];
        }
    }
    
    if ($img_path == '' OR $img_url == '')
    {
        return FALSE;
    }

    if ( ! @is_dir($img_path))
    {
        throw new Exception('Captcha path seems is not a directory !');
    }
    
    if ( ! is_really_writable($img_path))
    {
        //throw new Exception($img_path. ' Captcha directory is not writeable !');
    }
            
    if ( ! extension_loaded('gd'))
    {
        throw new Exception('Gd extension not found for captcha !');
    }        
    
    // -----------------------------------
    // Remove old images    
    // -----------------------------------
            
    list($usec, $sec) = explode(" ", microtime());
    $now = ((float)$usec + (float)$sec);
            
    $current_dir = @opendir($img_path);
    
    while($filename = @readdir($current_dir))
    {
        if ($filename != "." and $filename != ".." and $filename != "index.html")
        {
            $name = str_replace(".jpg", "", $filename);
        
            if (($name + $expiration) < $now)
            {
                @unlink($img_path.$filename);
            }
        }
    }
    
    @closedir($current_dir);

    // -----------------------------------
    // Do we have a "word" yet?
    // -----------------------------------
    
   if ($word == '')
   {
        $str = '';
        for ($i = 0; $i < $max_char; $i++)
        {
            $str .= substr($pool, mt_rand(0, strlen($pool) -1), 1);
        }
        
        $word = $str;
   }
    
    // -----------------------------------
    // Determine angle and position    
    // -----------------------------------
    
    $length    = strlen($word);
    $angle    = ($length >= 6) ? rand(-($length-6), ($length-6)) : 0;
    $x_axis    = rand(6, (360/$length)-16);            
    $y_axis = ($angle >= 0 ) ? rand($img_height, $img_width) : rand(6, $img_height);
    
    // -----------------------------------
    // Create image
    // -----------------------------------
            
    // PHP.net recommends imagecreatetruecolor(), but it isn't always available
    if (function_exists('imagecreatetruecolor'))
    {
        $im = imagecreatetruecolor($img_width, $img_height);
    }
    else
    {
        $im = imagecreate($img_width, $img_height);
    }
            
    // -----------------------------------
    //  Assign colors
    // -----------------------------------
    
    $bg  = html2rgb($background);
    $bg_color        = imagecolorallocate ($im, $bg[0], $bg[1], $bg[2]);
    $brd = html2rgb($border);
    $border_color    = imagecolorallocate ($im, $brd[0], $brd[1], $brd[2]);
    $txt = html2rgb($text);
    $text_color        = imagecolorallocate ($im, $txt[0], $txt[1], $txt[2]);
    $grd = html2rgb($grid);
    $grid_color        = imagecolorallocate($im, $grd[0],$grd[1],$grd[2]);
    $shd = html2rgb($shadow); 
    $shadow_color    = imagecolorallocate($im, $shd[0], $shd[1], $shd[2]);

    // -----------------------------------
    //  Create the rectangle
    // -----------------------------------
    
    ImageFilledRectangle($im, 0, 0, $img_width, $img_height, $bg_color);
    
    // -----------------------------------
    //  Create the spiral pattern
    // -----------------------------------
    
    $theta        = 1;
    $thetac        = 7;
    $radius        = 16;
    $circles    = 20;
    $points        = 32;

    for ($i = 0; $i < ($circles * $points) - 1; $i++)
    {
        $theta = $theta + $thetac;
        $rad = $radius * ($i / $points );
        $x = ($rad * cos($theta)) + $x_axis;
        $y = ($rad * sin($theta)) + $y_axis;
        $theta = $theta + $thetac;
        $rad1 = $radius * (($i + 1) / $points);
        $x1 = ($rad1 * cos($theta)) + $x_axis;
        $y1 = ($rad1 * sin($theta )) + $y_axis;
        imageline($im, $x, $y, $x1, $y1, $grid_color);
        $theta = $theta - $thetac;
    }

    // -----------------------------------
    //  Write the text
    // -----------------------------------
    
    $use_font = ($font_path != '' AND file_exists($font_path) AND function_exists('imagettftext')) ? TRUE : FALSE;
        
    if ($use_font == FALSE)
    {
        $font_size = 5;
        $x = rand(0, $img_width/($length/3));
        $y = 0;
    }
    else
    {
        $font_size    = 16;
        $x = rand(0, $img_width/($length/1.5));
        $y = $font_size+2;
    }

    for ($i = 0; $i < strlen($word); $i++)
    {
        if ($use_font == FALSE)
        {
            $y = rand(0 , $img_height/2);
            imagestring($im, $font_size, $x, $y, substr($word, $i, 1), $text_color);
            $x += ($font_size*2);
        }
        else
        {        
            $y = rand($img_height/2, $img_height-3);
            imagettftext($im, $font_size, $angle, $x, $y, $text_color, $font_path, substr($word, $i, 1));
            $x += $font_size;
        }
    }
    

    // -----------------------------------
    //  Create the border
    // -----------------------------------

    imagerectangle($im, 0, 0, $img_width-1, $img_height-1, $border_color);        

    // -----------------------------------
    //  Generate the image
    // -----------------------------------
    
    $img_name = $now.'.jpg';

    ImageJPEG($im, $img_path.$img_name);
    
    $img = "<img src=\"$img_url$img_name\" width=\"$img_width\" height=\"$img_height\" style=\"border:0;\" alt=\" \" />";
    
    ImageDestroy($im);
        
    return array('word' => $word, 'time' => $now, 'image' => $img);
}


/* End of file captcha.php */
/* Location: ./base/helpers/captcha.php */